To let your stomach heal, you will be advised a liquid diet as it isn’t advisable for you to eat for the first few days following Bariatric Surgery. You will very slowly transition back to solid foods. Your calorie consumption will be much less of what it used to be, and your diet will be completely different. It typically takes patients anywhere from two to six weeks to start feeling balanced and back to normal again.

It is also important that you drink approx (about 6-8 glasses) 1.5 – 2 L per day, as it's important that you remain well
hydrated... YOU MUST DRINK FLUIDS, not just water. If you only drink water, you may develop electrolyte abnormalities.  Keep the drink next to you and sip it slowly with a straw every 15 to 20 minutes.

Diet plan after Weight Loss Surgery:    

Generally, the diet pattern advised is: -

Weeks 1 & 2: Liquid diet - Oral rehydration fluid ORS (Electral or Walyte)  lemon water, musambi juice, coconut water, unsweetened, green / herbal tea, clear dal / veg / chicken soup, khichdi / rice water, dilute lassi made of double toned milk, Glucerna SR, (the taste can be improved by adding a few drops of rose water or some Elaich powder), Protienex in double toned Milk.

Weeks 3 & 4: Semi solid diet–  Should be of sauce consistency, something which doesn’t need to be chewed eg. Dalia, Patli Khichri, Peeli moong dal, Curd rice, Milk dalia, Milk suji, custard.

Weeks 5 & 6: Soft solid diet - Like Veg upma, Veg dalia, wheatflakes in milk, oatmeal, egg  white, well cooked vegetables like lauki, tori, kaddu, Dals, Veg Raita

Week 7 onwards: Normal diet (with necessary restrictions) chewed well and eaten slowly

Keeping a food diary is useful because it aids as a monitoring guide of the food intake to the patient. About 1200 calories and 60 to 70 g of protein should be the goal once the patient reaches the normal diet phase.  Healthy eating for weight loss surgery patients has two angles… what you eat and how you eat.

In general, there are 7 food principles to live by:

  1. Eat healthy - Fresh fruits and vegetables, such as Papaya, Melons, Apples, cucumber, Ghia / Lauki, Tori, Tinda, Spinnach, Cabbage, Cauliflower, Tomatoes, Sprouts in curd, Raita with Lauki / Cucumber
  2. Protein first - Protein is one of the most important nutrients for your body, and you need 60 to 80 grams a day in order to stay healthy. Egg white, Steamed fish / Chicken, Chicken soup, Soya bean dal, Nutri nuggets, Tofu,
    Cottage cheese made from double toned milk. 
  3. Keep your blood sugar stable – by eating on time 3 - 4 times a day at 6 to 8 hr intervals
  4. Drink the right amount of water at the right times
  5. Don’t snack
  6. Be religious about taking your Vitamins, Calcium and iron supplements
  7. How you eat is as important as what you eat
    • ​Stop eating before you feel full to avoid vomiting, diarrhoea, constipation and difficulty in swallowing and to prevent stomach stretching and weight regain.
    • Eat slowly and chew your food thoroughly
    • Do not drink during meals or up to an hour afterwards

Eating healthy means that your diet should consist primarily of FOG foods:

Farm – The food is raised on a farm (chicken, eggs, dairy products made of double toned milk)

Ocean – It comes from the ocean (fish)

Ground – It is grown in the ground (fruits, vegetables, nuts, whole grains)
When possible, avoid anything that was modified by humans in any way.

What NOT to eat 

The following foods should be eliminated from your diet forever…

  • Sugar, sugar-containing foods and concentrated sweets
  • Fruit juices
  • High-saturated fat, processed cheese,
  • Fried foods

Foods that may give you problems.

  

Carbonated beverages, White bread containing maida, Pasta, Rice, Red meat,   Cashew / Pea Nuts, Popcorn, foods high in fibre (Guava, Pears etc). Caffeine and Alcohol is best abstained from.

How you prepare your food is as important as what you buys

When cooking, bake, grill, poach or broil, don’t fry.
Use low fat (skimmed / double toned) milk instead of whole milk
Use chicken or vegetable broth instead of oil, replace oil in recipes with curd
Add spices or lemon juice to add flavour instead of olive oil or butter.

Side Effects after Bariatric Surgery
Nausea or vomiting is common within the first few months following weight loss surgery. How you eat is as important as what you eat when it comes to preventing nausea and vomiting. Avoid eating and drinking too quickly or too much, take small bites and chew your food thoroughly. Do not drink any liquids during your meals or within an hour afterwards. This can flush your meals through your new stomach which can cause you to eat more and
contribute to malabsorption and dumping syndrome.
Body aches
 – should pass with time. If they become too uncomfortable, talk with your doctor about which pain relievers are safe. You should avoid NSAIDs (non-steroidal anti-inflammatory drugs) such as Brufen or Combiflam.
Feeling weak, tired or cold
 – should also pass with time, especially once your new bariatric diet is in place and, as soon as you are feeling up to it, your exercise program has begun
Constipation – drinking more fluids, eating fibrous foods or taking fiber supplements and moving around regularly should help.
Diarrhea or loose stools
 - Is usually caused by intake of food not being cooked or stored hygienically, or as part of Dumping Syndrome. Introduce one new item at one time so that the offending item can be identified.
Dumping Syndrome,
especially after gastric bypass, is caused by rapid emptying of your stomach after a meal. This happens if water is drunk with or soon after meals OR of you have consumed high caloric drink / food. Symptoms include weakness, dizziness, flushing and warmth, nausea and palpitation and diarrhoea immediately or shortly after eating.  If you don't adopt
the right habits, this problem can continue over the long-term. 
Your emotional state
 may also be a little shaky immediately following surgery. It’s common for patients to feel scared, uncertain or moody due to hormonal changes and to the emotional effects of adjusting to a new life after weight loss surgery.
Skin changes such as acne or dry skin occur with some patients. The right bariatric diet and bariatric vitamins are your best defence. There are also many over the counter creams and lotions that can help. Worst case, partner with your
dermatologist to find a treatment that works.
Hair loss
 – this can be an alarming side effect of rapid weight loss, but it is only temporary. It happens in about half of all patients in the year following surgery. Proper nutrition is the best prevention, specially ensuring adequate protein and the right bariatric vitamins. Several other treatments can also help, including the application of special
shampoos, flax seed oil, biotin tablets or powder.

In order to maintain your weight loss and health improvement after weight loss surgery, you'll need to develop proper long-term diet and exercise habits. Otherwise, you will gain your weight back.